Method And System For Hybrid Radio Frequency Digital Beamforming

ABSTRACT

Methods and systems for hybrid radio frequency digital beamforming may include, in an electronic device comprising an antenna array including antennas arranged along first and second directions, beamforming signals in an analog domain along the first direction of the antenna array and beamforming signals in a digital domain along the second direction of the antenna array. The antenna array may include subsets of antennas, where each subset has a system-on-chip (SOC) with analog and digital beamforming circuitry. Signals may be beamformed in the analog domain by amplifying signals received by the antenna array using a configurable gain and shifting the phase of at least one of the amplified signals. The phase-shifted signals may be summed and converted to a digital signal. A frequency-dependent coefficient may be applied to the digital signal. The antenna array may have a fewer number of antennas along the first direction as compared to a number of antennas along the second direction.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application makes reference to and claims priority to U.S.Provisional Application Ser. No. 62/166,308 filed on May 26, 2015. Theabove identified application is hereby incorporated herein by referencein its entirety.

FIELD

Certain embodiments of the invention relate to semiconductor devices.More specifically, certain embodiments of the invention relate to amethod and system for hybrid radio frequency digital beamforming.

BACKGROUND

Conventional approaches for beamforming may be costly, cumbersome,and/or inefficient—e.g., they may be complex and/or time consuming,and/or may introduce asymmetry. Further limitations and disadvantages ofconventional and traditional approaches will become apparent to one ofskill in the art, through comparison of such systems with some aspectsof the present disclosure as set forth in the remainder of the presentapplication with reference to the drawings.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with the present invention as set forth inthe remainder of the present application with reference to the drawings.

BRIEF SUMMARY

A system and/or method for hybrid radio frequency digital beamformingsubstantially as shown in and/or described in connection with at leastone of the figures, as set forth more completely in the claims.

Various advantages, aspects and novel features of the present invention,as well as details of an illustrated embodiment thereof, will be morefully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A illustrates an example electronic system that may utilize abeamforming antenna array, in accordance with an example embodiment ofthe disclosure.

FIG. 1B depicts a large-scale transceiver array of a wireless accessnetwork.

FIG. 2A depicts components of an example implementation of thelarge-scale transceiver array of FIG. 1.

FIG. 2B depicts components of another example implementation of thelarge-scale transceiver array of FIG. 1.

FIG. 3 depicts an example implementation of the transceiver-arraymodules of FIGS. 2A.

FIG. 4 illustrates hybrid RF digital beamforming, in accordance with anexample embodiment of the disclosure.

FIG. 5A illustrates example beamforming receiver circuitry in accordancewith an example embodiment of the disclosure.

FIG. 5B illustrates transmitter circuitry with hybrid RF digitalbeamforming, in accordance with an example embodiment of the disclosure.

FIG. 6 is an expanded view of a signal path comprising in-phase andquadrature paths, in accordance with an example embodiment of thedisclosure.

FIG. 7 is a flowchart illustrating an example process for hybrid RFdigital beamforming.

DETAILED DESCRIPTION

Certain aspects of the disclosure may be found in hybrid radio frequency(RF) digital beamforming. Exemplary aspects of the invention maycomprise, in an electronic device comprising an antenna array comprisingantennas arranged along first and second directions, beamforming signalsin an analog domain along the first direction of the antenna array andbeamforming signals in a digital domain along the second direction ofthe antenna array. The antenna array may comprise subsets of antennas,where each subset comprises a system-on-chip (SOC) with analog anddigital beamforming circuitry. Each SOC may be coupled to other SOCsusing a digital interface. Signals may be beamformed in the analogdomain by amplifying signals received by the antenna array using aconfigurable gain and shifting the phase of at least one of theamplified signals. The phase-shifted signals may be summed and convertedto a digital signal utilizing an analog-to-digital converter (ADC). Afrequency-dependent coefficient may be applied to the digital signal.The antenna array may have a fewer number of antennas along the firstdirection as compared to a number along the second direction. A trackingmodule in the electronic device may subtract an amplified and filteredversion of a signal received by a first antenna from an amplified andfiltered version of a signal received by a second antenna arranged inthe first direction from the first antenna.

As utilized herein, “and/or” means any one or more of the items in thelist joined by “and/or”. As an example, “x and/or y” means any elementof the three-element set {(x), (y), (x, y)}. As another example, “x, y,and/or z” means any element of the seven-element set {(x), (y), (z), (x,y), (x, z), (y, z), (x, y, z)}. As utilized herein, the terms “block”and “module” refer to functions than can be implemented in hardware,software, firmware, or any combination of one or more thereof. Asutilized herein, the term “exemplary” means serving as a non-limitingexample, instance, or illustration. As utilized herein, the term “e.g.,”introduces a list of one or more non-limiting examples, instances, orillustrations.

FIG. 1A illustrates an example electronic system that may utilize abeamforming antenna array, in accordance with an example embodiment ofthe disclosure. Referring to FIG. 1A, there is shown an electronicsystem 100 with an antenna array 103, a radio frequency (RF) front end105, and processing module 107.

The antenna array 103 may comprise one or more antenna elements that areoperable to receive wireless RF signals for processing by the RF frontend 105 and the processing module 107 in the electronic system 100. Inanother example scenario, the antenna 103 may be operable to transmitwireless RF signals generated by the processing module 107. As theantenna is arranged in an array, beamforming is therefore enabled, withthe transmission or reception of signals being directional, due toconstructive and destructive interference between signals. To changedirectionality when transmitting, the phase and amplitude at eachantenna element, and when receiving, signals from the different antennaelements may be combined such that an expected pattern of RF signal ispreferentially received.

The number of elements in a given direction may indicate the range andresolution. For example, as shown in FIG. 1A, the antenna array 103 mayhave two rows and five columns of antenna elements, resulting in morebeamforming capability in the horizontal direction as compared to thevertical direction. Such an embodiment may be useful in an automotiveapplication, for example, where more horizontal range is needed thanvertical.

The RF front end 105 may comprise amplification, mixing, filtering, andanalog-to-digital or digital-to-analog conversion functions, forexample, and therefore may comprise low-noise amplifiers, programmablegain amplifiers, power amplifiers, low-pass, band-pass, and high-passfilters, analog-to-digital converters (ADCs), and digital-to-analogconverters (DACs). Programmable gain amplifiers may be utilized in thebeamforming capabilities of the antenna array 103.

The electronic system 100 may comprise suitable circuitry forimplementing various aspects of the present disclosure. The electronicsystem 100 may be configured to support performing, executing or runningvarious operations, functions, applications and/or services. Theelectronic system 100 may be used, for example, in executing computerprograms, playing video and/or audio content, gaming, performingcommunication applications or services (e.g., Internet access and/orbrowsing, email, text messaging, chatting and/or voice callingservices), providing networking services (e.g., WiFi hotspot, Bluetoothpiconet, Ethernet networking, cable or satellite systems, and/or active4G/3G/femtocell data channels), or the like.

In some instances, the electronic system 100 may enable and/or supportcommunication of data. In this regard, the electronic system 100 mayneed to communicate with other systems (local or remote), such as duringexecuting, running, and/or performing of operations, functions,applications and/or services supported by the electronic system 100. Forexample, the electronic system 100 may be configured to support (e.g.,using suitable dedicated communication components or subsystems) use ofwired and/or wireless connections/interfaces, which may be configured inaccordance with one or more supported wireless and/or wired protocols orstandards, to facilitate transmission and/or reception of signals(carrying data) to and/or from the electronic system 100. In thisregard, the electronic system 100 may be operable to process transmittedand/or received signals in accordance with applicable wired or wirelessprotocols.

Examples of wireless standards, protocols, and/or interfaces that may besupported and/or used by the electronic system 100 may comprise wirelesspersonal area network (WPAN) protocols, such as Bluetooth (IEEE 802.15);near field communication (NFC) standards; wireless local area network(WLAN) protocols, such as WiFi (IEEE 802.11); cellular standards, suchas 2G/2G+ (e.g., GSM/GPRS/EDGE, and IS-95 or cdmaOne) and/or 2G/2G+(e.g., CDMA2000, UMTS, and HSPA); 4G standards, such as WiMAX (IEEE802.16) and LTE; Ultra-Wideband (UWB), and/or the like.

Examples of wired (and in some cases wireless) standards, protocols,and/or interfaces that may be supported and/or used by the electronicsystem 100 may comprise Ethernet (IEEE 802.3), Fiber Distributed DataInterface (FDDI), Integrated Services Digital Network (ISDN), cabletelevision and/or internet access standards (e.g., ATSC, DVB-C, DOCSIS,etc.), in-home distribution standards such as Multimedia over CoaxAlliance (MoCA), and Universal Serial Bus (USB) based interfaces.

Examples of signal processing operations that may be performed by theelectronic system 100 comprise, for example, filtering, amplification,analog-to-digital conversion and/or digital-to-analog conversion,up-conversion/down-conversion of baseband signals, encoding/decoding,encryption/decryption, and/or modulation/demodulation.

In some instances, the electronic system 100 may be configured to enableor support input/output operations, such as to allow user interactionsthat may be needed for controlling the electronic system 100 oroperations thereof (e.g., to allow operators to provide input orcommands for controlling location specific marketing, or obtain outputor feedback pertaining to it). In this regard, the electronic system 100may comprise components or subsystems for enabling interactions with auser (e.g., end-user or installer), so as to obtain user input and/or toprovide user output.

In some instances, the electronic system 100 may enable or supportinput/output operations, such as to allow providing output to and/orobtaining input from user(s) of the electronic system 100. In thisregard, the electronic system 100 may comprise components or subsystemsfor enabling obtaining user input and/or to provide output to the user.For example, the electronic system 100 may enable or supportinput/output operations for allowing user interactions which may beneeded for controlling the electronic system 100 or operations thereof(e.g., allowing operators to provide input or commands for controllingcertain functions or components, to output or provide feedbackpertaining, etc.). Also, the electronic system 100 may be operable tosupport input and/or output of multimedia data. For example, theelectronic system 100 may enable or support generating, processing,and/or outputting of video and/or acoustic signals, such as via suitableoutput devices or components (e.g., displays, loudspeakers, etc.). Inthis regard, the output signals may be generated based on content, whichmay be in digital form (e.g., digitally formatted music or the like).Similarly, the electronic system 100 may enable or support capturing andprocessing of video and/or acoustic signals, such as via suitable inputdevices or components (e.g., cameras, microphones, etc.), to generate(e.g., to store or communicate) corresponding data. The correspondingdata may be in digital form (e.g., digitally formatted music, video, orthe like).

The electronic system 100 may be a stationary system (i.e. beinginstalled at, and/or configured for use only in particular location). Inother instances, however, the electronic system 100 may be a mobiledevice—i.e. intended for use on the move and/or at different locations.In this regard, the electronic system 100 may be designed and/orconfigured (e.g., as handheld device) to allow for ease of movement,such as to allow it to be readily moved while being held by the user asthe user moves, and the electronic system 100 may be configured toperform at least some of the operations, functions, applications and/orservices supported on the move.

Examples of electronic systems may comprise handheld electronic devices(e.g., cellular phones, smartphones, or tablets), computers (e.g.,laptops, desktops, or servers), dedicated media devices (e.g.,televisions, game consoles, or portable media players, etc.), set-topboxes (STBs) or other similar receiver systems, and the like. Thedisclosure, however, is not limited to any particular type of electronicsystem.

In operation, the electronic system 100 may be operable to performvarious operations, functions, applications and/or services. Forexample, in some instances, electronic system 100 may be operable totransmit and/or receive RF signals via the antenna array 103, which maybe operable to provide beamforming of signals transmitted and/orreceived from the electronic system 100. The antenna array 103 may havemore elements along one axis as compared to a perpendicular axis. Inthis example scenario, digital beamforming may be utilized along thefirst axis with a larger number of elements while simpler analogbeamforming may be utilized along the perpendicular axis with fewerelements.

FIG. 1B depicts a large-scale transceiver array of a wireless accessnetwork. The array 102 is mounted on a building and connected to abaseband unit 108 via one or more cables 106 (e.g., fiber optic cables,coaxial cables, or any other suitable type of cable). The array 102communicates with mobile subscribers 110 a and 110 b.

In an example scenario, the array 102 may be operable to beamformtransmitted and received signals and may utilize hybrid RF digitalbeamforming where analog steering is utilized along one axis and digitalbeamforming is utilized along another axis. Such a beamformingconfiguration may be utilized where less steering is needed along oneaxis (e.g., horizontal) and more steering is needed along a second axis(e.g., vertical) in which case analog steering may be utilizedhorizontally and digital for vertical steering. This is in contrast toautomotive beamforming, where little vertical steering is needed andmore horizontal steering is needed.

FIG. 2A depicts components of an example implementation of thelarge-scale transceiver array of FIG. 1. The example array 102 in FIG.2A comprises a plurality of modules 204 (any particular module 204 iscalled out as 204 _(RC), where R and C are the module's row and columnindexes, respectively) and baseband module 108 coupled via cables 106.Although twelve modules are shown for illustration, an array 102 maycomprise any number of modules (e.g., 32, 64, 128, or any other number).

The modules 204 may, for example, be installed in a manner similar toinstalling tiles. They may be laid out in a regular pattern and adheredto the wall using any suitable fastener such as glue, screws, etc.

Each of the modules 204 comprises an antenna element 206 (any particularantenna element 206 is called out as 206 _(rc), where 1≦r≦R, 1≦c≦C, andC is the total number of rows in the array, and C is the total number ofcolumns in the array). A subset of the modules 204 (e.g., every Nthmodule, where N=4 in the example shown) comprise transceiver circuits202 (any particular transceiver circuit 202 is called out as 202 _(x),where 1≦x≦X and X is the total number of transceivers in the array 102(e.g., X=(R*C)/4 in the example of FIG. 2A).

Each of the transceiver circuits 202 transmits and receives via arespective subset of the antenna elements 206. In FIG. 2A, eachtransceiver circuit 202 is shown connected to its respective antennaelements 206 via links 220, which may be wired, optical fiber, and/orwireless links. In an example implementation, such wireless links mayuse broadband near-field communication (BNC) links as, for example,described in U.S. Patent Application Publication 20130210352 titled“Method And System For Broadband Near-Field Communication Utilizing FullSpectrum Capture (FSC) Supporting Ranging,” which is hereby incorporatedherein by reference.

In an example scenario, the transceiver circuits 202 may providebeamforming capability along two axes with digital beamforming along oneand analog beamforming along the other. For example, the two rows ofantennas may provide a large degree of steering along the horizontaldirection with digital beamforming and less beamforming in the verticaldirection with analog beamforming.

In the example implementation of FIG. 2A, each of the transceivers isconnected to the baseband unit 108 via a respective cable 106. Such anarchitecture may reduce the amount of data that each cable is requiredto carry but may also introduce a lot of complexity and cost.Accordingly, an alternative is shown in FIG. 2B in which only a subsetof the transceivers 202 connect to the baseband unit and the remainingtransceivers are connected in a daisy chain fashion via links 252.

FIG. 2B depicts components of another example implementation of thelarge-scale transceiver array of FIG. 1. The example array 102 in FIG.2B comprises a plurality of modules 204 (any particular module 204 iscalled out as 204 _(RC), where R and C are the module's row and columnindexes, respectively) and baseband module 108 coupled to the firstmodule 204 ₁₁ via cable 106. Although twelve modules are shown forillustration, an array 102 may comprise any number of modules (e.g., 32,64, 128, or any other number). In this embodiment only a single cable106 is coupled to the first module and signals are then connected in adaisy chain fashion via links 252.

FIG. 3 depicts an example implementation of the transceiver-arraymodules of FIGS. 2A and 2B. For clarity of illustration, only two of themodules, 204 ₁₁ and 204 ₁₃ are shown. In the example implementationshown, each of the example modules 204 comprises four antennas 206, atransceiver circuit 202, and a circuit assembly 384. The circuit 202 maybe a single integrated circuit die (e.g., CMOS). The circuit assembly384 may comprise components which are undesirable to integrate on chipwith the circuit 202. For example, for an implementation in which thelinks 106 are fiber optic cables, the circuit assembly 384 may comprisea laser diode and laser detector mounted on a PCB. In an examplescenario, four antennas may be coupled to each circuit 202 as shownfurther with respect to FIG. 4.

In the example implementation shown, each of the transceiver circuits202 comprises transmit/receive switches 302 ₁-302 ₄, receive analogfront-end circuits 338 ₁-338 ₄, receive digital signal processingcircuits 340 ₁-340 ₄, demodulator/decoder circuits 342 ₁-342 ₄,interface 382, encoder/modulator circuits 354 ₁-354 ₄, transmit digitalsignal processing circuits 356 ₁-356 ₄, and transmit analog front-endcircuits 358 ₁-358 ₄.

Each of the transmit/receive switches 302 is configurable between atransmit configuration in which a respective transmit analog front-end358 is connected to a respective antenna element 206 and a receiveconfiguration in which a respective receive analog front-end 338 isconnected to a respective antenna element 206. In practice, the switches302 cannot provide perfect isolation. Consequently, even when a switch302 is configured for transmit, some signal will leak through to thereceive front end.

Each receiver analog front-end 338 comprises an amplifier 330, a mixer332, a filter 334, and an analog-to-digital converter 336. Each transmitanalog front-end 358 comprises a digital to analog converter 360, afilter 362, a mixer 364, and a power amplifier 366.

Each receive digital signal processing circuit 340 ₁-340 ₄ may beoperable to, for example, perform filtering, calibration (e.g.,calibration of in-phase and quadrature phase signal paths), and/or thelike. In addition the receive digital signal processing circuits 340₁-340 ₄ may be operable to beamform and may utilize analog beamformingalong an axis requiring less steering and digital beamforming along anaxis requiring more steering. In an example scenario, two rows ofantennas with multiple antennas along one axis, e.g., 2×8, may providemore steering along the 8-antenna axis utilizing digital beamforming andless steering along the 2 rows utilizing analog beamforming.

Similarly, digital and analog beamforming may be utilized fortransmission of signals. Accordingly, each of the transmit digitalsignal processing circuits 356 may be operable to, for example, performbeamforming with higher steering while analog beamforming may beutilized for an axis with less beam steering requirements

Each demodulator/decoder 342 may be operable to demodulate receivedsignals in accordance with modulation schemes used for the accessnetwork in which array 102 participates, and decode received signals inaccordance with FEC algorithms schemes used for the access network inwhich array 102 participates.

Each encoder/modulator 354 may be operable to modulate signals to betransmitted in accordance with modulation schemes used for the accessnetwork in which array 102 participates, and encode signals to betransmitted in accordance with FEC algorithms schemes used for theaccess network in which array 102 participates.

The interface circuit 382 may be operable to transmit and receive inaccordance with protocols in use on the link 106. In an exampleimplementation where the link 106 is a fiber optic cable, the interface382 may be operable to demodulate the signal received from the laserdetector and modulate a signal for output to the laser diode.

In another example implementation, some of the circuitry shown incircuits 202 may instead be implemented in the baseband unit 108. Forexample, modulation, demodulation, FEC encoding, and FEC decoding may bedone in the baseband unit 108. This may reduce the amount of data thatneeds to be delivered over links 106 but at the expense of increasedcomplexity in the circuit 202. As another example, the relatively-lessmemory/processor intensive demodulation may be performed in the circuit202 to output log likelihood ratios (LLRs) to the baseband unit 108where the relatively-more memory/processor intensive decoding may takeplace.

FIG. 4 illustrates hybrid RF digital beamforming, in accordance with anexample embodiment of the disclosure. Referring to FIG. 4, there isshown an array of antennas, labeled XY for column X and row Y, atransceiver chip 403 for each set of 4 antennas, and PA/LNA/Switchcircuitry 405 for each pair of antennas. Applications for such an arraymay comprise satellite receivers with phased-array feeds, automotiveradar, and millimeter wavelength backhaul, for example.

In an example scenario, the transceiver chips 403 may be operable toprovide hybrid beamforming for the antenna array 400 where analogbeamforming is utilized along one axis, e.g., vertical in this case, anddigital beamforming may be utilized along another axis, e.g., horizontalaxis along the rows of antennas in FIG. 4. Digital beamforming may beutilized in the horizontal axis along the rows of antennas resulting inmore steering as compared to the vertical direction with analogbeamforming. A high-speed digital interface 411 may couple each of thetransceivers 403 enabling digital beamforming along the horizontal axis.

The PA/LNA/Switch circuitry 405 shown for each pair of antennas maycomprise RF front end circuitry for transmitting and receiving RFsignals including one or more transmit/receive switches enabling bothtransmission and reception of signals via the antennas. Accordingly, thethe PA/LNA/Switch circuitry 405 may comprise amplification, mixing,filtering, and analog-to-digital or digital-to-analog conversionfunctions, for example, and therefore may comprise low-noise amplifiers,programmable gain amplifiers, power amplifiers, low-pass, band-pass, andhigh-pass filters, analog-to-digital converters (ADCs), anddigital-to-analog converters (DACs). Programmable gain amplifiers may beutilized in the beamforming capabilities of the antenna array 400.

FIG. 5A illustrates example beamforming receiver circuitry in accordancewith an example embodiment of the disclosure. Referring to FIG. 5A,there is shown a receiver circuit 500 with digital and analogbeamforming capability. Four antennae 501 are coupled to the receivercircuit 500 where each path may comprise a separate in-phase andquadrature (I and Q) path, as illustrated by the expanded path shown inFIG. 5, comprising I and Q paths. Each path may comprise an LNA 503, anI/O mixer 505, low-pass filters 507 and 513, an analog-to-digitalconverter (ADC) 515, and a VCO/PLL 511 with phase shifter module 509 foreach pair of I/O paths. Digital and analog beamforming circuitry mayreceive the I and Q signals. The LNAs 503 may comprise a configurablegain and the phase shifter 509 enables a configurable phase differencebetween signals output by the mixers 505.

The receiver circuit 500 may comprise wideband signal paths 520 andnarrowband signal paths 510, where the narrowband paths 510 may beutilized for tracking and direction finding (T/DF) using the T/DF summer529, and the wideband paths 520 may be utilized for beamforming and maycomprise an adder 517, low-pass filter 519, and an ADC 521 for receivingand digitizing the filtered and down-converted signals from each I/Opath. The resulting digital signal may be amplified by a complexfrequency-dependent weight, or coefficient, 523 before beingcommunicating to digital beamforming circuitry 525.

Analog beamforming may be enabled by the amplitude and phase adjustmentsof the received signals by the LNAs 503 and phase shifter 509, and thencombining them in the analog domain by the summers 517, which each sumthe two analog signals from a pair of antennas 501. Theconstructive/destructive interference of various received signals thenresults in beamforming by each vertical pair of antennas.

Digital beamforming may be carried out by the digital beamformingcircuitry 525, which receives digital signals that have been weighted bythe complex frequency-dependent weight 523 from each pair of antennas501 as well as from other antenna pairs in the array. In this manner,higher complexity processing may be performed in the digital domain bythe digital beamforming circuitry 525 for more complex and/or widerrange beamforming, while lower complexity, or narrower range,beamforming may be performed in the analog domain before digitizing.

A high-speed digital I/O 527 may communicate beamforming data betweentransceiver circuits, thereby enabling higher steering along desiredaxes, horizontal in this example. Accordingly, the digital beamformingcircuit 525 in a plurality of transceiver circuits may enablebeamforming from a plurality of antennae and analog beamforming may beutilized for each pair in the vertical direction.

FIG. 5B illustrates transmitter circuitry with hybrid RF digitalbeamforming, in accordance with an example embodiment of the disclosure.Referring to FIG. 5B, there is shown a transmitter 550 with example RFtransmit circuitry, similar to the receiver circuitry of FIG. 5A, but inreverse direction for transmission. As with FIG. 5A, the transmitter 550comprises narrowband and wideband signal paths 510 and 520,respectively, and may provide analog beamforming along one axis, e.g.,vertical, and digital beamforming in another axis, e.g., horizontal. Inan example scenario, a transmit/receive switch may enable switchingbetween transmission and reception of the circuits 500 and 550 with RFhybrid beamforming, as illustrated by T/R switches 302 in FIG. 3.

In operation, signals for transmission may be communicated to eachtransmitter 550, where the signals may enable beamforming in the digitaldomain, via the digital beamforming circuitry 525, as well as analogbeamforming. The components of the transmitter module 550 may besubstantially similar to the receiver of FIG. 5A, but with somedifferences, such as the T/DF 629 comprising a splitting operationinstead of summing, and the filters 619 generating two outputs to enablethe digitally beamformed transmission signal. In addition, the poweramplifiers 603 may amplify the signals for transmission with variablegain levels, which along with the phase control of the phase shifter509, enables analog beamforming.

FIG. 6 is an expanded view of a signal path comprising in-phase andquadrature paths, in accordance with an example embodiment of thedisclosure. Referring to FIG. 6, there is shown I and Q transceiver path600 comprising mixers 605A-605D, low pass filters 607A and 607B,VCO/PLLs 611A and 611B, phase shifters 609A and 609B, summer 617, ADCs621A and 621B, and digital channel select filters 619A and 619B.

The I and Q transceiver path 600 may be operable to extract I and Qsignals from an input signal by down-converting the input signal withtwo mixers 605A and 605B with clock signals 90 degrees out of phase. TheI and Q signals may then be processes with filters 607A and 607B,converted to digital signals using the ADCs 621A and 621B, and thendesired digital channels may be selected by the digital selectionfilters 619A and 619> In an example scenario, the resulting signals maybe recombined using the summer 617.

FIG. 7 is a flowchart illustrating an example process for hybrid RFdigital beamforming. In block 702, RF signals may be received by anarray of antennas with a first axis and a second axis. In block 704,analog beamforming may be configured for the first axis where less beamsteering is needed. In block 706, digital beamforming may be configuredfor the second axis. In an example scenario, the signals may compriseI/O signals.

In block 708, signals may be generated for transmission. In block 710,analog beamforming may be configured for the first antenna axis and inblock 712 digital beamforming may be configured for the second antennaaxis. The signals may then be transmitted in block 714 using thedetermined/configured beamforming parameters.

In an embodiment of the disclosure, a method and system may comprise oneor more circuits in an electronic device comprising an antenna arrayhaving antennas arranged along first and second directions. The one ormore circuits are operable to beamform signals in an analog domain alongthe first direction of the antenna array and beamform signals in adigital domain along the second direction of the antenna array. Theantenna array may comprise subsets of antennas, where each subsetcomprises a system-on-chip (SOC) with analog and digital beamformingcircuitry. Each SOC may be coupled to other SOCs using a digitalinterface. Signals may be beamformed in the analog domain by amplifyingsignals received by the antenna array using a configurable gain andshifting the phase of at least one of the amplified signals. Thephase-shifted signals may be summed and converted to a digital signalutilizing an analog-to-digital converter (ADC). A frequency-dependentcoefficient may be applied to the digital signal. The antenna array mayhave a fewer number of antennas along the first direction as compared toa number of antennas along the second direction. A tracking module inthe electronic device may subtract an amplified and filtered version ofa signal received by a first antenna from an amplified and filteredversion of a signal received by a second antenna arranged in the firstdirection from the first antenna.

Accordingly, aspects of the invention may be realized in hardware,software, firmware or a combination thereof. The invention may berealized in a centralized fashion in at least one computer system or ina distributed fashion where different elements are spread across severalinterconnected computer systems. Any kind of computer system or otherapparatus adapted for carrying out the methods described herein issuited. A typical combination of hardware, software and firmware may bea general-purpose computer system with a computer program that, whenbeing loaded and executed, controls the computer system such that itcarries out the methods described herein.

One embodiment may be implemented as a board level product, as a singlechip, application specific integrated circuit (ASIC), or with varyinglevels integrated on a single chip with other portions of the system asseparate components. The degree of integration of the system willprimarily be determined by speed and cost considerations. Because of thesophisticated nature of modern processors, it is possible to utilize acommercially available processor, which may be implemented external toan ASIC implementation of the present system. Alternatively, if theprocessor is available as an ASIC core or logic block, then thecommercially available processor may be implemented as part of an ASICdevice with various functions implemented as firmware.

While the invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiments disclosed, but that the present inventionwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. An electronic device, the device comprising: oneor more circuits coupled to an antenna array comprising antennasarranged along first and second directions, said one or more circuitsbeing operable to: beamform signals in an analog domain along the firstdirection of the antenna array; and beamform signals in a digital domainalong the second direction of the antenna array.
 2. The electronicdevice according to claim 1, wherein the antenna array comprises subsetsof antennas, each subset comprising a system-on-chip (SOC) with analogand digital beamforming circuitry.
 3. The electronic device according toclaim 2, wherein each SOC is coupled to other SOCs using a digitalinterface.
 4. The electronic device according to claim 1, wherein theone or more circuits are operable to beamform signals in the analogdomain by amplifying signals received by the antenna array using aconfigurable gain and shifting the phase of at least one of theamplified signals.
 5. The electronic device according to claim 4,wherein the one or more circuits is operable to sum the phase-shiftedsignals.
 6. The electronic device according to claim 5, wherein the oneor more circuits is operable to convert the summed signal to a digitalsignal utilizing an analog-to-digital converter (ADC).
 7. The electronicdevice according to claim 6, wherein the one or more circuits isoperable to apply a frequency-dependent coefficient to the digitalsignal.
 8. The electronic device according to claim 1, wherein theantenna array has a fewer number of antennas along the first directionas compared to a number of antennas along the second direction.
 9. Theelectronic device according to claim 1, wherein the one or more circuitscomprise a tracking module that subtracts an amplified and filteredversion of a signal received by a first antenna from an amplified andfiltered version of a signal received by a second antenna arranged inthe first direction from the first antenna.
 10. The electronic deviceaccording to claim 1, wherein the one or more circuits is operable toprocess in-phase and quadrature (I and Q) signals.
 11. A method forcommunication, the method comprising: in an electronic device comprisingan antenna array comprising antennas arranged along first and seconddirections: beamforming signals in an analog domain along the firstdirection of the antenna array; and beamforming signals in a digitaldomain along the second direction of the antenna array.
 12. The methodaccording to claim 11, wherein the antenna array comprises subsets ofantennas, each subset comprising a system-on-chip (SOC) with analog anddigital beamforming circuitry.
 13. The method according to claim 12,wherein each SOC is coupled to other SOCs using a digital interface. 14.The method according to claim 11, comprising beamforming signals in theanalog domain by amplifying signals received by the antenna array usinga configurable gain and shifting the phase of at least one of theamplified signals.
 15. The method according to claim 14, comprisingsumming the phase-shifted signals.
 16. The method according to claim 15,comprising converting the summed signal to a digital signal utilizing ananalog-to-digital converter (ADC).
 17. The method according to claim 16,comprising applying a frequency-dependent coefficient to the digitalsignal.
 18. The method according to claim 11, wherein the antenna arrayhas a fewer number of antennas along the first direction as compared toa number of antennas along the second direction.
 19. The methodaccording to claim 11, comprising, in a tracking module in theelectronic device, subtracting an amplified and filtered version of asignal received by a first antenna from an amplified and filteredversion of a signal received by a second antenna arranged in the firstdirection from the first antenna.
 20. An electronic device comprising:one or more circuits coupled to an antenna array comprising antennasarranged along first and second directions, with more antennas beingarranged along the first direction as compared to those arranged alongthe second direction, said one or more circuits being operable to:beamform signals in an analog domain along the first direction of theantenna array; and beamform signals in a digital domain along the seconddirection of the antenna array.